Skylab was a short-lived operation, less than a year, but the time of the operational operation was greater than that of all the US manned space flights up to that time. The amount of information obtained was enormous.
Once again the United States proved superiority in space exploration. Skylab was not the first space laboratory. The first to launch a space laboratory were the Russians - Soliot. The inability of the Russians to open launchers on the scale of the Saturn 5 forced them to use the launcher they had at the time, the Proton, capable of putting an 18-ton payload into orbit around the Earth. The result was a small laboratory and necessarily a smaller volume. The capacity of the laboratory is smaller and the stay time of the crew, three astronauts, is shorter than that of Skylab. The Soliot program ran into problems in its early days. The first Soyuz 10 crew had problems operating the lab. The second team carried out their plan, but the final result ended in tragedy. The astronauts returned to Israel without a soul. They perished due to a malfunction in their Soyuz spacecraft. Two attempts were made to launch a space laboratory. In the first experiment, the laboratory was destroyed during the launch. In the second attempt, the laboratory disintegrated while in orbit around the Earth. The Russian space programs were temporarily frozen.
Skilab also started out in a failed way. The reason for this lies not in a basic deficiency in the laboratory itself, but in the failure to utilize metallurgy (the science that deals with the strength of materials). The result was a torn sun visor and the loss of one of the sun visors. The lab's engineers didn't say desperate. The first Skylab crew did not launch as planned, one day after the launch of the lab, but a few days later. During this time, the fault was thoroughly studied and after the dispatch of the team, it was fixed. During the operation of the station, additional problems arose, such as the problems that arose with the gyroscopes, the broken systems were not left in their condition, but repaired in the most efficient way. It has been proven once again that manned flight is more important than unmanned flight. In manned flights there is room for improvements and repairs. Complete and expensive systems are salvaged and reusable. In unmanned flights, the probability of shutting down a system or spacecraft in its entirety is greater and the result is that a huge fortune goes down the drain and so does a lot of information that is lost.
NASA made every effort for the success of the space laboratory. Beyond the technological and scientific achievement of her rescue there were other reasons for this:
A. Failure means a cut in the space program and a delay in the development of the space shuttle.
B Delaying the examination of all the technical and scientific issues related to space laboratories that are most essential for programs of this type and their investigation.
third. Rejecting research in everything related to people's prolonged stay in space, whether it is space laboratories or flights to the planets.
d. Prestige - The failure of Skylab would have dealt a heavy blow to NASA. This is after its great successes in space operations, including the Apollo program.
NASA did not disappoint. The space lab served all the crews that staffed it. Furthermore, with one of the two large solar shelves operating, and less electrical energy than planned, the astronauts stayed in it for 172 days instead of 140. Skylab was a short operation, less than a year, but the operational operation time was greater than that of all the US manned space flights until So. The amount of information obtained was enormous. The Apollo program focused on one subject and that is the moon. The Scilab focused on three topics: the Earth - wise use of it for the benefit of all humanity, astronomy - the study of the solar system, the comet Kohotek and space exploration. Biology - space medicine. The laboratory had to stay in space for 8-10 years.
The division of labor in Skilab
The Skilab program was designed for 240 manned and unmanned work days. In practice, 271 working days were implemented, 12.9% more than planned and they included:
855 hours of medical experiments.
755 hours of astronomical telescope observation instead of 565.
412 Astrophysical observations.
294 technical experiments.
90 terrestrial observations and 11 observations when the intensity of the sun was weaker.
32 materials experiments.
The Skylab pilots also performed work for the US Department of Defense. In total, they brought to Israel a load of 840 kg, which included:
46,146 photographs of national minerals, and a 6.4 km long data film.
182,842 photographs of the telescope films.
Medical findings
Dr. Kerwin, a Skylab 2 team member, discovered that the concepts of up and down have meaning in weightlessness and this is done according to an arbitrary decision where up and where down. This phenomenon is related to the mechanical balance of the inner ear. After returning to Israel, Jack Lusma broke household utensils several times. The explanation for this phenomenon was that he got used to objects flying in the air and not falling to the ground. Evan Griot was unable to lie in his bed or get out of it in the dark. It turned out that his balance deficits were related to his lack of visual field.
All three teams suffered from a bad mood at the beginning of their journey, but it improved within a few days. From the total of the six months of activity in the space laboratory, it became clear that there are no physiological restrictions for a prolonged stay in space. On the other hand, the body loses weight, loses muscle mass, loses red cells and plasma, loses calcium from the bones and sodium and potassium electrolytes from the body fluids. These changes reach a certain level on days 35-40 of the flight when the body gets used to the weightlessness. Moreover, these changes are 100% reversible when the body returns to normal gravity.
Each of the first crew lost 2.7 kg during the flight, and their full adaptation time to gravity ranged from 21 to 24 days. Each of the other team lost 3.6 kg, and the time to adapt to Earth's gravity was seven days. Each of the third team lost 1.35 kg, and the adaptation time was 4.5 days. The reason for these improvements lies in the gymnastics exercises performed by the last two teams, in the additional food they received to reduce weight loss, and in the sleeping time.
National findings
1. Reasonable chances of finding copper deposits near Ely in Nevada, eastern USA.
2. Identify areas full of fruit trees such as lemons in Mexico, near the Rio Grande River.
3. Sorting crops and growing vegetables with an accuracy of 92% compared to 82%" of the ERTS satellite.
4. Identification of urbanized areas near Poonoke, Arizona.
5. A surprising result obtained is how easily plankton "surfaces" can be discovered. The latter team discovered "red tides" that had spread like an epidemic in Florida waters in the years before these flights. This tide is created by micro-organisms that are toxic to fish, marine molluscs and even humans. The red tide increases in cycles to a great extent. In the photographs, you see the red tide surrounded by green plankton "surfaces" that serve as nutrients for them and allow them to spread large and fast.
6. Using the radiometer and the spectrometer (dispersion meter) you can measure the speed of winds over the oceans and the amount of precipitation.
7. There is a small concentration of temperatures in the oceans which has a significant role in creating climate.
It seems that the radiometer and the spectrometer answered fundamental questions concerning the development of a similar device for meteorological satellites in the future, and provided engineering knowledge for the design of a radar device for observing the earth in a large frequency range like in Skylab.
Solar finds
The latest information gathered by the Skylab pilots led to a better understanding of the Sun's corona. Until the launch of the space lab, it was thought that the corona developed gradually. Following this information it became clear that the corona developed "violently" and rapidly by exploding "bubbles". Each of these bubbles tears an opening in the corona - a dark area that allows gases to escape along the magnetic field lines without the help of the sun. It was also believed that the solar wind blows from these holes. The Skylab observations showed that this belief is wrong.
The origin of the holes is probably inside the sun and they can serve as a key to understanding its internal structure and, surprisingly, also to the rate of its energy production. As in the earth, so also in the sun there are energy differences. It appears to radiate 10 times more than the thermonuclear processes occurring within it.
Once every two weeks, cold clouds with ionized gases at a temperature of 3300 degrees appear on the surface of the sun. Astronomers recognized this phenomenon as relatively rare. Bright spots on the surface of the sun that were thought to be only in the equatorial region are spreading over the entire surface of the sun like smallpox.
Among the astrophysicists, the assessment grew stronger that long-term changes in solar energy are probably an important factor in the development of the ice ages on Earth. Just as the cycle of sunspots is responsible for cyclical changes in the growth rate of trees in periods of 5.5, 11 and 22 years.
The Earth's climate, especially in the Northern Hemisphere, is significantly improved by the passage of a magnetic front from the Sun. This occurs four times in one solar cycle (once every 6.5 days). The magnetic front followed a three-day drop in cyclonic activity. It turned out that these magnetic fronts are anchored in the Sun, close to the coronal holes. A proposal was made to use these holes and the passage of magnetic fronts in the future as additional means of weather forecasting.
The space laboratory was launched during one of the solar cycles. It turned out that in the last days of the cycle, the number of sunspots drops to zero. The sun then shows both active and passive faces. There are days when the number of sunspots reached 130, greater than the record recorded in 1969. This phenomenon allowed the three teams to bring important photographs with them. The latter team photographed full bursts of flames from the moment they erupted until they died down. Two solar eclipses were also photographed.
Planetary finds
Comet Kohotek was tracked and the transit of Mercury was photographed, something that can only be done from Earth 16 times in a hundred years. Ultraviolet observations revealed that Mercury had an atmosphere even before Mariner 10 reached it.
metallurgical findings
Indium and antimony crystals formed on Earth were partially melted and regrown in space. Surprisingly they are free from heterogeneous cracking under space conditions. Furthermore, the causes of surface tension in molten materials are located on the outside of the new crystal surface and do not penetrate inside. Brazed materials and brass, the only ones subject to the effect of capillary forces fill large spaces to give perfect corners. The lack of convection forces allows the growth of semiconductor crystals using the vapor technique grown with germanium and selenium in an iodine atmosphere. At Skilab they created a crystal 2.54 cm long, 10% thicker than any material created on Earth.
One of the options raised following the Skylab program was the creation of superconducting alloys. When these materials are cooled below a certain transition temperature they can conduct electrons with zero resistance. Under current conditions such materials must be cooled to several degrees Kelvin. In the laboratories of the Bell company, alloys of this type were obtained by vapor deposition of nibium and germanium at 232 degrees Kelvin. The development of superconducting alloys at 78 degrees Kelvin allows the use of cooled nitrogen which is cheap and safe instead of expensive liquid hydrogen and helium and enables superconducting power lines.
Metallurgists hoped based on these experiments to arrive at the structure and chemical composition of alloys that play an important role in superconducting temperatures. Like germanium vapor deposition - gold at a certain transition temperature will be on conductors, but a molten or distressed mixture will not. A germanium gold sample that was melted in Skylab and re-solidified without gravity and following convection currents showed conductivity. A tin-antimony lead sample formed in zero gravity showed a higher transition temperature than that prepared on Earth.
The treatment of molten metals at temperatures close to 1000 degrees was achieved by a static and acoustic system. The standing waves generated by a sound source directed at a reflecting surface showed the ability to lift and hold a disk with a diameter of 7.5 mm and drops of almost spherical liquids with a diameter of 0.625 cm. Lenses made of glass are free of impurities until they are almost optically perfect.
